Use the @Entity annotation to specify that a class is an entity.
@Entity
Note:
The entity class must also be listed in your persistence.xml file, unless you set the tag <exclude-unlisted-classes> to false.
persistence.xml
<exclude-unlisted-classes>
For more information, see Chapter 2 "Entities" in the JPA Specification.
http://jcp.org/en/jsr/detail?id=338